Pen grip



FIG. 1 is a front side bottom perspective view of a pen grip, showing my new design;

FIG. 2 is a side elevational view thereof;

FIG. 3 is a bottom plan view thereof; and,

FIG. 4 is a top plan view thereof.

The broken lines depicting environmental structure are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a pen grip, as shown and described. 